Sneezes, snots, and sniffles (Proceedings)

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Acute onset of sneezing and nasal discharge are common with upper respiratory infections (particularly in young cats or those in multi-cat environments), nasal foreign bodies, nasal trauma, and rarely coagulopathies. Nasal foreign body is discussed later in the article.

Acute nasal disease

Acute onset of sneezing and nasal discharge are common with upper respiratory infections (particularly in young cats or those in multi-cat environments), nasal foreign bodies, nasal trauma, and rarely coagulopathies.  Nasal foreign body is discussed later in the article.

Upper respiratory infections

Nasal (sneezing,discharge), ocular, and systemic signs (fever, malaise) are common.   Mild serous nasal/ocular discharge may be the first detectable sign.  The most common causative agents are FHV-1 (80%), FCV, Chlamydia and Mycoplasma. Co-infections are common.  Infections are frequently complicated by overgrowth of normal flora.  Acute upper respiratory signs can often be treated empirically and do not require tests to identify the exact viral or bacteriologic agent.  Empiric antibiotic treatment should target the organisms most commonly encountered (e.g., Chlamydia, Mycoplasma, and normal flora).   Famcyclovir (62.5 mg PO q12h x 14 days) is safe and can be effective in reducing FHV-1 associated signs.  Oral interferon (30 IU PO q24h) and lysine (250-500 mg/cat PO q12h) may reduce signs in acute FHV-1 infection.   Anorexic, dehydrated patients require fluid and nutritional support (warming food, wiping nose clean, appetite stimulants, +/- feeding tube).

Chlamydophila felis occurs in 10-31% of cats with upper respiratory tract disease and mainly causes acute and chronic conjunctivitis.  Young and elderly cats are particularly susceptible.  Signs include ocular discharge, redness, blepharospasm, nasal discharge, and occasionally decreased appetite and fever.  Positive serology correlates with infection in unvaccinated cats.  A prolonged course of doxycycline (at least 4 weeks) is necessary to eliminate infection and should continue for at least 2 weeks beyond resolution of signs. All cats in the household should be treated.  Azithromycin will not clear the infection.

Mycoplasma are part of the normal mucosal flora of the upper respiratory and urogentical tracts and of the eyes. Opportunistic infections can arise in susceptible animals.  Ocular manifestations include discharge and blepharospasm.  Culture and PCR can both identify the organism.  Treatment requires topical ophthalmic tetracycline as well as systemic antibiotic therapy with a drug that is effective against this organism (doxycycline, azithromycin, fluoroquinolones, chloramphenicol).

Chronic nasal disease          

When nasal signs become chronic or when facial deformity is present, further investigation into an underlying cause is indicated.  Younger cats are more likely to be diagnosed with viral/bacterial infections and nasopharyngeal polyps.  Neoplasia is more common if new but persistent symptoms arise in patients over 8 years of age.  Secondary bacterial infection is common with many nasal diseases and may lead to a temporary resolution of clinical signs with antibiotic treatment. 

History

Signs of many nasal diseases overlap.  The most common are sneezing, nasal discharge and obstruction of airflow (from accumulated secretions or masses).  A thorough workup is required so that the most appropriate treatment can be selected.  A detailed history should investigate onset, duration, character, and seasonality of signs.

Examination

A thorough exam in patients with chronic nasal signs should include evaluation of ocular and nasal discharge (character, severity, unilateral vs. bilateral), air movement through the nostrils, facial symmetry, palpation of nose and sinuses for pain, size of submandibular lymph nodes, oral exam with cursory dental exam, and fundic exam.  Facial deformity may occur with advanced neoplasia and fungal rhinitis.  Fundic lesions may be present in some cats with Cryptococcosis.

 

Diagnostic evaluation

A CBC, biochemical profile, and urinalysis are performed to evaluate the general health status and identify comorbid conditions.  A typical workup of chronic nasal disease requires anesthesia and includes computed tomography (or skull radiographs if CT is unavailable), rhinoscopy with biopsy, and a thorough oral and dental exam.  Computed tomography is often superior to radiography for evaluating nasal disease.

Cryptococcosis is the most common cause of fungal rhinitis in the cat. Exposure (inhalation) occurs through pigeon droppings or soil contaminated with avian excreta.  Common signs include uni- or bilateral nasal discharge (serous, mucopurulent, or hemorrhagic).  A swelling over the bridge of the nose (35%), proliferative lesions protruding from a nostril, or cutaneous nodules/ulcer on the face may be noted in some and can provide a source for cytologic sampling.  Nasopharyngeal granulomas can form and may obstruct airflow resulting in dyspnea. Signs must be differentiated from other causes of nasal disease, particularly neoplasia.  Imaging assists with this and determines extent of disease. Cytology or biopsy usually provide definitive diagnosis.  The LAT (latex agglutination test; sensitivity 95%, specificity 100%), can be useful in suspected cases where a diagnosis remains elusive.  Itraconazole (5 mg/kg q12h) is the treatment of choice and is continued for 1 to 2 months after resolution of signs or negative LAT test (whichever is later).  Monitor for hepatotoxicity and GI signs.  Fluconazole is associated with less side effects.  Surgical excision of large nasopharyngeal granulomas may be beneficial to allow better drug penetration.

Nasal aspergillosis is rare in cats.  Clinical signs and imaging findings are similar to what is seen in the dog.  Turbinate destruction can be extensive and is best demonstrated with computed tomography, which can also determine if there is frontal sinus involvement.  Diagnosis is confirmed by direct visualization of fungal plaques or identification of fungal elements in histologic specimens obtained via rhinoscopy and/or sinuscopy.  Treatment with topical clotrimazole infusion can be effective in the cat but may be associated with a higher risk of complications.

Foreign bodies in cats most often become lodged in the nasopharynx after an unsuccessful swallowing attempt or when the material is regurgitated back up.  Common signs are acute paroxysmal sneezing, pawing at the nose or face, unilateral nasal discharge, snorting, gagging, and repeated attempts at swallowing.  A prompt investigation is warranted when these signs are present.  Foreign bodies that persist will result in progressive nasal discharge.  Secondary bacterial or fungal infections may develop.  Radiographs usually do not show any abnormalities unless the foreign body is radiopaque.  Radiographic evidence of bony lucencies in the nasal cavity of a patient with a chronic foreign body suggests a secondary fungal infection.

Diagnosis of nasopharyngeal foreign bodies is established by rhinoscopic exam of the nasopharynx (which also allows for retrieval) or via nasal flush.  With the nasal flush, the endotracheal tube cuff is first checked to reduce the risk of aspiration, gauze is placed in the caudal nasopharynx, and 20-, 35-, or -60 ml syringes are used to forcefully flush saline from the front of the nose caudally.  The gauze is then examined for retrieved material.  Occasionally foreign bodies may be lodged in the rostral nares.  Inspection of the rostral nose in these cases can be started with an otoscope cone.  CT and rigid rostral rhinoscopy may be necessary to achieve a diagnosis and rule out other causes.  Unless a foreign body is very strongly suspected, nasal flush should be performed after CT, since it can alter imaging findings.

Rhinotomy may be needed in cases were retrieval has been unsuccessful by other means (e.g. stubborn plant awns, long-standing foreign bodies encased in granulation tissue).  Some foreign bodies evade detection despite an appropriate workup.

Nasopharyngeal polyps are benign inflammatory growths that occur most commonly in young cats (<2 years of age).  They originate from the Eustachian tube and the extend either into the pharynx (NP polyps), grow within the tympanic cavity (middle ear polyps), or extend through a ruptured tympanum into the external ear canal (external ear polyps).  Signs reflect the location of the polyp (nasal discharge, sneezing, stertor, dyspnea, dysphagia, gagging, head shaking, pawing at ears, vestibular signs. 

Oral exam under anesthesia with retraction of the soft palate will reveal most nasopharyngeal masses. If very large, it may be palpable through the soft palate.  Otoscopic examination and evaluation of the bullae via CT or radiography should be performed to rule out concurrent external and/or middle ear involvement.  With skull radiographs, thickening of the bullae with increased soft tissue density indicates otitis media.  Computed tomography is more sensitive than radiographs for detecting otitis media.  Increased fluid or soft tissue density within the bulla or bulla walls that appear thick/thin/or distended are indications of otitis media.

In patients with no evidence of otitis media, polyps can be removed via traction avulsion. Grasp the stalk at its base with Allis tissue forceps and then twist vigorously until the stalk with attached mass break free.  Recurrence rates with traction removal (17% to 50%) may be reduced further if a 14-day tapering course of prednisolone is used after the procedure (starting at 1-2 mg/kg/day).  Recurrence is unlikely in patients where ventral bulla osteotomy is performed to remove the polyp.   The feline tympanic bulla has two chambers; the epithelial lining of both chambers must be removed to prevent recurrence.  A culture of the bulla is obtained at surgery and empiric antibiotics prescribed while awaiting results.  Otitis interna can be a complication of bulla osteotomy and occurs in about 40% of patients.  Transient Horner's syndrome is common after both procedures and usually resolves within 1 month.

 

Nasal neoplasia is a common cause of nasal signs that develop in an older cat.  Lymphoma is the most common tumor type, followed by adenocarcinoma and squamous cell carcinoma.  Signs are often present for weeks to months and can include nasal discharge, stertor, facial deformity, sneezing, epistaxis, poor appetite, epiphora.  Radiation therapy or chemotherapy, alone or in combination, can be effective for patients with nasal lymphoma and have the potential to result in long survivals. Chemotherapy is required in patients with systemic lymphoma.  Radiation therapy can markedly improve survival in cats with nasal carcinoma.  Supportive measures should be used as dictated by the individual patient to help maintain the cat's appetite (warm food, appetite stimulants, antiemetics, +/- feeding tube).  Piroxicam (0.3 mg/kg PO q48-72h) can reduce inflammation and nasal signs in some cats with nonlymphoproliferative neoplasia.

Chronic rhinosinusitis (CRS) is the most common chronic upper respiratory tract disease in cats and results in mild to moderate intermittent or progressive clinical signs (sneezing, nasal discharge, stertor).  Signs can be uni- or bilateral and discharge can occasionally be blood-tinged.  The pathogenesis is unknown.  Prior acute viral upper respiratory tract disease may lead to development of this condition in some cats.  Cats of any age can be affected. 

Computed tomography may be normal, or show fluid accumulation and variable turbinate destruction (mimics neoplasia and fungal disease).  Hyperemic mucosa, with normal or variably destroyed turbinates, and copious discharge are found on rhinoscopy.  Inflammation, ulceration, hyperplasia, fibrosis, and necrosis are seen histologically.  Cultures (aerobic, anaerobic, Mycoplasma) of deep nasal biopsy or flush specimens should guide treatment of secondary bacterial infections.  Flushing of secretions from the nasal cavity can provide temporary but significant relief.  The endotracheal tube cuff must be leak-checked, the throat packed with gauze, and the head pointed downward (for drainage) to prevent aspiration during the flush. 

CRS can be frustrating to treat.  Recurrences are expected.  Recurrent infections are managed with prolonged courses of antimicrobials preferably based on deep nasal cultures.  Antibiotics commonly recommended include doxycycline, clindamycin, amoxicillin-clavulanate, marbofloxacin, enrofloxacin, and azithromycin.  If a response is noted, treatment should continue for 6-8 weeks.  Lysine (250-500 mg/cat PO q12h) can benefit some cats and can be safely used long term.  Saline nasal drops, if tolerated, make nasal secretions easier to expel.  Piroxicam (0.3 mg/kg PO q48-72h) may lessen signs in some patients.  Monitoring for GI and renal toxicity is required.

Frontal sinus ablation is considered as a last resort procedure in select cases.  While it may improve clinical signs in some patients, significant intraoperative hemorrhage and persistent postoperative anorexia (loss of smell) are risks.

Nasopharyngeal (NP) stenosis is a rare diagnosis but is being recognized with increasing frequency.  It results when a thin fibrous membrane forms in the nasopharynx and progressively occludes the nasopharynx.  Most form as a result of prior inflammatory event affecting the upper respiratory tract.  Some may be present from birth.  Decreased nasal air flow results in stertorous breathing.

Impaired drainage of nasal secretions into the caudal pharynx leads to nasal discharge, secondary bacterial infection, and sneezing.  Diagnosis is made by direct visualization of the stenotic membrane in the nasopharynx on retroflex rhinoscopic exam.  NP stenosis must be differentiated from processes that cause stenosis of the NP via external compression (e.g., neoplasia).  When the distinction is not clear, computed tomography can be useful.  Treatment involves removal or dilation of the stenotic membrane.  In cases where a thin membrane is present, dilation using a valvuloplasty balloon under endoscopic guidance can often be successful.  Dilation is followed by a short course of corticosteroid administration to reduce scare tissue and avoid rapid reformation of the stricture.  Recurrence is possible and may take weeks, months, or more than a year.  Return of symptoms dictates when a repeat dilation should be performed.  Cases where the stenosis involves an extensive area of tissue +/- bone (instead of just a thin membrane), treatment can be challenging and potentially very frustrating.  Other procedures that may be tried include: bougienage, surgery, and stenting.

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